Airmen&#39;s seat harnesses



April 13, 1965 MARTIN 3,178,223-

AIRMEN'S SEAT HARNESSES Filed Oct. 9, 1962 2 Sheets-Sheet 1 A ril 13,1965 J. MARTIN 3,178,223

AIRMEN'S SEAT HARNESSES Filed 001:. 9, 1962 2 Sheets-Sheet 2 UnitedStates Patent 3,178,223 AIRMENS SEAT HARNESSES James Martin, SouthlandsManor, Southlands Road, Denham, near Uxbridge, Middlesex, England FiledOct. 9, 1962, Ser. No. 229,375 Claims priority, application GreatBritain, Oct. 11, 1961, 36,534/ 61 5 Claims. (Cl. 297-385) Thisinvention concerns airmens seat harnesses.

An airmans harness frequently comprises two principal parts which may beseparate or combined, namely, one part (usually called the parachuteharness) which serves to connect the airman to his parachute and, whereprovided, to his inflatable dinghy and/or survival pack, and the secondpart (usually called the seat harness) which serves to retain the airmanin his seat.

The present invention is particularly concerned with airmens seatharnesses and is applicable to independent seat harnesses and also toseat harnesses forming a part of a combined harness.

One defect of most conventional airmens seat harnesses is their failureto counter, effectively, the tendency for an airman to be displaced awayfrom his seat cushion and/or parachute and/ or survival pack (allhereinafter included in the term seat cushion) as a result of invertedflight or when other negative-G conditions prevail, there being aserious danger that 'on the airman being so displaced, the seat cushionwill move forwardly relatively to the seat pan to such an extent that,in the case of a pilots seat cushion, it may interfere with the movementof the control column of the aircraft in subsequent flying or so that,in any case, the weight of the airman will be transmit ted through theseat cushion to the front wall of the seat pan withthe consequence thatthis may be distorted and possibly torn and so present a marked dangerto the safety of the airman, this being especially the case where theseat is an ejection seat and if ejection follows upon such displacementof the seat cushion.

Considerable efforts have been expanded in an endeavour to improveairmens seat harnesses in such a way that the aforementioned defect willbe minimised and the airman be firmly held in his seat in an aircraft inthe said adverse conditions but, so far as I am aware, no

really successful solution to the problem has hitherto been achieved,arrangements so far proposed being complicated and tedious to don and/or reducing the comfort of the airman when seated.

It is at present customary for an airmans seat harness to include lapstraps having their rear ends anchored to the seat pan so as to passupwardly and forwardly around the buttocks of the airman and over histhighs, the front ends of such straps being adapted to be fasteneddirectly or indirectly to a quick-release device or box (hereinafterreferred to as a quick-release box) usually situated in front of theairman in the region of his navel. In many instances, for example in thecase 'of aircraft ejection seats, the rear ends of the lap straps arereleasably anchored to the seat pan and the airmans seat harnessincludes further straps which pass from the quickrelease box and aroundor over the upper part of the airmans trunk and/or over his shouldersbefore being connected releasably to the back of the seat at the upperpart thereof.

With any arrangement in which lap straps pass upwardly and forwardlyfrom the lower part of the seat around the thighs and legs of the airmanto be anchored directly or indirectly to a quick-release box in front ofthe airman, there is still some freedom for the airman to move away fromhis seat cushion in inverted flight or in other circumstances in whichnegative-G conditions pre- "ice vail, with the consequential dangersthat have hereinbefore been explained, for it will be appreciated thatthe said lap straps do not exert a direct pull on' the airman towardsthe base of the seat pan but exert a pull in a more or less diagonalmanner from the region of the airmans navel towards the rear lower partof the seat pan, so that the front ends of the lap straps may pivot orare, for example as the aircraft is inverted, around the anchorages ofthe lap straps to the aircraft seat and so permit the airman to moveaway from his seat cushion;

According to this invention there is provided an airmans seat harnesscomprising a pair of lap straps having their rear ends anchored oradapted to be anchored to an aircraft seat and a pair of holding-downstraps anchored or adapted to be anchored to extend upwardly between theairmans legs from laterally spaced-apart locations 'on the base of suchseat, each lap strap being associated with an individual holding-downstrap to constitute a strap pair one member of which extends through aneye at the free end of the other member and has its free end adapted forfastening by a quick-release box, one member of such pair havinglength-adjusting means.

Preferably the lap straps have eyes at their free ends and are equippedwith length-adjusting means, the holding-down straps extending throughsuch eyes and terminating in fittings for coupling to the quick-releasebox.

Thus preferred forms of seat harness in accordance with the inventioncomprise a pair of lap straps having their rear ends anchored or adaptedto be anchored to an aircraft seat and a pair of holding-down strapsanchored or adapted to be anchored to extend upwardly between theairmans legs from laterally spaced-apart locations on the base of suchseat, each holding-down strap extending through an eye at the free endof the adjacent lap strap and having its free end adapted for fasteningby a quick-release box and each lap strap incorporating length-adjustingmeans.

Although the said two holding-down straps may be entirely separate fromone another and individually anchored to the seat, the two straps mayconveniently be formed from a single length of woven webbing, the strapbeing anchored to the seat by being passed freely through a pair oflaterally spaced-apart inverted U-shaped loops or equivalent meanssymmetrically arranged at the front of the seat so that the holding-downstraps will, whentensioned, form an open loop of such dimensions as toreduce the danger of injury to the airman in the event of his beingthrust forwardly with respect to the seat.

The invention may be embodied in seat harnesses for use with aircraftejection seats, the harnesses in such cases being adapted to provide forrelease of the airman from his seat at the appropriate stage of anejection sequence.

Thus in the case of an independent seat harness for use with an ejectionseat the various straps (including the holding-down straps) of suchharness may all be anchored to the seat by locks that may be opened,e.g. by a suitable automatic mechanism, at the appropriate stage in anejection sequence to free the harness from the seat. Alternatively, thequick-release box may be utilised to free the airman from the seatharness during ejection, this quick-release box (and any other such boxfor fastening other straps of the seat harness) conveniently beingadapted for operation during ejection by a suitable automatic mechanism.

In the case of a combined parachute and seat harness for use with anejection seat, the various straps (including the holding-down straps) ofthe seat harness part of such combined harness may all be anchored tothe seat by locks openable during ejection to free the harness from theseat.

In order that the invention may he more readily under- 6 stood oneembodiment of the same will now be described by way of example withreference to the accompanying drawings in which:

FIGURE '1 is a perspective view of an airman seated and secured in anaircraft ejection seat by means of seat harness in accordance with theinvention; and

FIGURE 2 is a front view of the airman, seat and harness of FIGURE 1.

The drawings show an airman 1 seated in an aircraft ejection seat 2 andsecured in such seat by means of an independent seat harness inaccordance with the invention.

The seat harness comprises a pair of chest straps 3, 4 which extendaround the chest of the airman 1, a pair of lap straps 5, 6 which extendfrom anchorages 7 at the sides of the seat pan 8 of the seat 2 about thethighs of the airman, and a pair of holding-down or anti-G straps 9,:19.

The chest straps 3, 4 are anchored to the back of the seat 2 and havetheir free ends fastened by a first quickrelease box 11 while the lapstraps 5, 6 terminate in eyes formed by ring fittings 12, 13,respectively.

The holding-down straps 9, areconstituted by a single length of webbingthat extends through spaced-apart inverted loops 14, 15 on the front ofseat 2, the ends of such Webbing extending through the ring fittings 12,13 respectively and being fastened by a second quick-release box 16.

In this particular embodiment, the quick-release boxes 11, 16 aremounted on a breast plate 17 and are adapted for automatic actuation,during an ejection of the seat 2, by a time-delay mechanism,diagrammatically indicated at 18, operating the boxes via flexiblecables 19 and 20. The lap straps 5, 6 each have a length-adjustingbuckle 21 by means of which these straps may be tensioned to the airmanschoice. It will be appreciated that'tensiom ing of these straps alsoetfects tensioning of the holdingdown straps 9, 10.

It will be understood that the use of two holdingdown straps that aretensioned by the lap straps to form an open loop between the airmanslegs serves to restrain the airman in a manner that is unlikely to leadto injury, against his being thrust forwardly with respect to the seatpan.

I claim:

1. For an aircraft seat, an airmans seat harness comprising: a pair oflap straps adapted to be anchored to the seat to extend about theairmans lower body and a pair of holding-down straps adapted to extendupwardly between the airmans legs from laterally spaced-apart locationson the base of the seat, each lap strap being associated with anindividual holding-down strap, to constitute a strap pair, an eye at thefree end of one member of each such pair, the other member of such pairextending through said eye; a quick-release box for fastening the freeends of said other members of the strap pairs; and length-adjustingmeans for a member of such strap pairs.

2. For an aircraft seat, an airmans seat harness comprising: a pair oflap straps adapted to be anchored to the seat to extend about theairmans lower body and a pair of holding-down straps adapted to beanchored to extend upwardly between the airmans legs from laterallyspaced-apart locationson the base of the seat; an eye at the free end ofeach lap strap, each holding-down strap extending through the eye of theadjacent lap strap; a quick-release box for fastening the free ends ofthe holding-down straps; and length-adjusting means for each lap strap.

3. An aircraft seat having an airmans seat harness comprising: a pair oflap straps anchored to the seat for extending about the lower body "ofan airman seated therein; a pair of laterally spaced-apart anchorages atthe front of the seat base; an individual holding-down strap secured toeach said anchorage; an eye at the free end of each said lap strap, theadjacent holding-down strap extending through such eye; a quick-releasebox for securing the free ends of the holding-down straps; andlength-adjusting means for each lap strap.

4. The aircraft seat of claim 3, wherein said holdingdown straps areconstituted by a single length of webbing.

5. The aircraft seat of claim 4, wherein said anchorages comprisespaced-apart anchorage loops through which said webbing length isthreaded.

References Cited by the Examiner UNITED STATES PATENTS (1st add. to No.805,814)

FRANK B. SHERRY, Primary Examiner.

1. FOR AN AIRCRAFT SEAT, AN AIRMAN''S SEAT HARNESS COMPRISING: A PAIR OFLAP STRAPS ADAPTED TO BE ANCHORED TO THE SEAT TO EXTEND ABOUT THEAIRMAN''S LOWER BODY AND A PAIR OF HOLDING-DOWN STRAPS ADAPTED TO EXTENDUPWARDLY BETWEEN THE AIRMAN''S LEGS FROM LATERALLY SPACED-APARTLOCATIONS ON THE BASE OF THE SEAT, EACH LAP STRAP BEING ASSOCIATED WITHAN INDIVIDUAL HOLDING-DOWN STRAP, TO CONSTITUTE A STRAP PAIR, AN EYE ATTHE FREE END OF ONE MEMBER OF EACH SUCH PAIR, THE OTHER MEMBER OF SUCHPAIR EXTENDING THROUGH SAID EYE; A QUICK-RELEASE BOX FOR FASTENING THEFREE ENDS OF SAID OTHER MEMBERS OF THE STRAP PAIRS; AND LENGTH-ADJUSTINGMEANS FOR A MEMBER OF SUCH STRAP PAIRS.